The ritual of a bedtime story is a sacred one for many parents and their children — letting the kids turn the pages, pointing out colorful characters and enjoying the stories together. But while plenty of parents love the tradition of a paper book, e-books are gaining on physical books.

Picture books weren’t a great sell back when e-readers sported black-and-white screens, but now some popular books even have their own apps on newer color tablets. SmartMoney says publishing revenue in the pre-18 book market has jumped 233% in the first quarter of 2012.

“It’s the fastest growing category in trade,” says a spokeswoman for the Association of American Publishers.

In a survey in the U.K. carried out in part by literacy charity The Reading Agency, almost half of parents say they read books to their kids on e-readers or tablets, or let them do the reading themselves. About a quarter of those parents went even further, and said they’d bought a child an e-reader for their very own.

Teens are still more interested in print versions, while little kids are jumping on the technology train pretty early: Children aged 7 to 12 think of e-books like toys and find them “fun and cool,” according to another recent survey. Those kids might love e-books for the simple fact that they’ve never known a world without them.

Now we just have to sit back and wait for the first e-reader pop-up book. Holograms in 3-D, anyone?